This invention provides one kind of control circuit system of the decorative light sets, especially point out that utilize two kind of mutually circulated controlling out-put of signal, so that let the decorative light sets have a continuous and pursuing regularly, reversible twinkling action of control circuit, said control circuit has provided one executive control in order to make system control of first, second decoding means, due to the logic transfer of output of executive control is quick, stable, so that the whole electric control system be able to increase more stability of decorative light action, the decorative light sets have established series connection planning, depend on how much of consuming power factor of decorative light sets and change the number of series connection, coordinate with the variety of series connection design to diversify its pursuing regularity, reversible twinkling so that it will have more increasing of peoples attraction. In recent year, the industry and commerce have rapid development, and lead the whole economical activity, especially in business world, the trade is become more active, therefore due to the commercial means is renew, break through continuously, so the competitive press is getting more and more serious, therefore, how to attract people's attention effectively, this is already fixed as a more important theme in the market place. In former times, it is mostly adopted big signboard or refreshing neon lamp advertisement in the ordinary market place to attract the attention of customers, in recent years, it is used to be utilized the street trees and hanging the decorative light sets on the trees of both side walk of street, it is not only beautiful and dignified and more saving electricity than neon light, it is extremely ideal, however a conventional decorative light sets are mostly adopted the mother lamp which is produced light up and turn off the lights in order to form an irregular twinkle effect of whole series of decorative light sets, like this, it is only forming a simple light up and turn off twinkle of whole decorative light sets and can't reach to regularly, plurality of twinkle effect, it is really to need some improvement, applicant has considered the several defect of conventional decorative light sets also study very hard, in addition to many years of fabrication and design experiences, after study and research, finally I have accomplished this invention.